Hello, I seem to be able to reproduce the OP’s problem, much to my chagrin.
My current hobo (with 17 Strength and Disease Resistance) has not experienced any alcohol withdrawal for a couple of weeks now and he still has constant common colds. The “you feel like you have a cold coming on…” message literally pops up after the coughing messages, which I’m guessing translates to my cold subsiding before suddenly coming back with a vengeance pretty much seconds after. How does that make sense?
I decided to follow the tips here and lived a pretty healthy life in those weeks, literally spending every single day sleeping with a proper intake of cold medicine, vitamins, food and water in-between. Just recently, I noticed my common cold disappearing… and in its place was influenza. At that point I pretty much gave up.
The common cold was a minor problem in the previous versions, and was relatively easy to prevent/get rid of. Not sure why it’s becoming so persistent now. Even if hobos aren’t the healthiest of specimens, this is just plain absurd, especially considering that my hobo is pretty beefy and disease resistant to boot.
EDIT: Oh, this is with 0.8 Romero, by the way.
If it helps, this was the setup I used for my character (I maximised the points and turned off skill rust to get an easier playthrough).
STR: 17, DEX: 15, INT: 16, PER: 11
+ve traits: Animal Empathy, Disease Resistant, Fast Healer, Gourmand, Light Eater, Night Vision, Packmule, Pain Resistant, Poison Resistant, Quick, Robust Genetics
-ve traits: Far-Sighted, Forgetful, Glass Jaw, Heavy Sleeper, Hoarder, Jittery, Near-Sighted, Poor Hearing, Trigger Happy, Truth Teller, Ugly
Profession: Hobo
I would send you the save file, but considering world gen files and stuff I have no idea how to do that properly or which files exactly to send.